examples/webgl_buffergeometry_instancing_dynamic.html

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<html lang="en">
<head>
	<title>three.js webgl - indexed instancing (single box), dynamic updates</title>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
	<style>
		body {
			color: #ffffff;
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			text-align: center;
			font-weight: bold;
			background-color: #000000;
			margin: 0px;
			overflow: hidden;
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		#info {
			position: absolute;
			top: 0px;
			width: 100%;
			padding: 5px;
		}

		a {
			color: #ffffff;
		}

		#webglmessage a {
			color: #da0;
		}

		#notSupported {
			width: 50%;
			margin: auto;
			border: 2px red solid;
			margin-top: 20px;
			padding: 10px;
		}
	</style>
</head>
<body>

	<div id="container"></div>
	<div id="info">
		<a href="http://threejs.org" target="_blank" rel="noopener">three.js</a> - indexed instancing (single box), dynamic updates
		<div id="notSupported" style="display:none">Sorry your graphics card + browser does not support hardware instancing</div>
	</div>

	<script src="../build/three.js"></script>

	<script src="js/WebGL.js"></script>
	<script src="js/libs/stats.min.js"></script>

	<script id="vertexShader" type="x-shader/x-vertex">
		precision highp float;

		uniform mat4 modelViewMatrix;
		uniform mat4 projectionMatrix;

		attribute vec3 position;
		attribute vec3 offset;
		attribute vec2 uv;
		attribute vec4 orientation;

		varying vec2 vUv;

		// http://www.geeks3d.com/20141201/how-to-rotate-a-vertex-by-a-quaternion-in-glsl/

		vec3 applyQuaternionToVector( vec4 q, vec3 v ){

			return v + 2.0 * cross( q.xyz, cross( q.xyz, v ) + q.w * v );

		}

		void main() {

			vec3 vPosition = applyQuaternionToVector( orientation, position );

			vUv = uv;

			gl_Position = projectionMatrix * modelViewMatrix * vec4( offset + vPosition, 1.0 );

		}
	</script>

	<script id="fragmentShader" type="x-shader/x-fragment">
		precision highp float;

		uniform sampler2D map;

		varying vec2 vUv;

		void main() {

			gl_FragColor = texture2D( map, vUv );

		}
	</script>

	<script>

		if ( WEBGL.isWebGLAvailable() === false ) {

			document.body.appendChild( WEBGL.getWebGLErrorMessage() );

		}

		var container, stats;
		var camera, scene, renderer, mesh;
		var offsetAttribute, orientationAttribute;

		var lastTime = 0;

		var moveQ = new THREE.Quaternion( 0.5, 0.5, 0.5, 0.0 ).normalize();
		var tmpQ = new THREE.Quaternion();
		var currentQ = new THREE.Quaternion();

		init();
		animate();

		function init() {

			container = document.getElementById( 'container' );

			camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 1, 1000 );

			scene = new THREE.Scene();
			scene.background = new THREE.Color( 0x101010 );

			// geometry

			var instances = 5000;

			var bufferGeometry = new THREE.BoxBufferGeometry( 2, 2, 2 );

			// copying data from a simple box geometry, but you can specify a custom geometry if you want

			var geometry = new THREE.InstancedBufferGeometry();
			geometry.index = bufferGeometry.index;
			geometry.attributes.position = bufferGeometry.attributes.position;
			geometry.attributes.uv = bufferGeometry.attributes.uv;

			// per instance data

			var offsets = [];
			var orientations = [];

			var vector = new THREE.Vector4();
			var x, y, z, w;

			for ( var i = 0; i < instances; i ++ ) {

				// offsets

				x = Math.random() * 100 - 50;
				y = Math.random() * 100 - 50;
				z = Math.random() * 100 - 50;

				vector.set( x, y, z, 0 ).normalize();
				vector.multiplyScalar( 5 ); // move out at least 5 units from center in current direction

				offsets.push( x + vector.x, y + vector.y, z + vector.z );

				// orientations

				x = Math.random() * 2 - 1;
				y = Math.random() * 2 - 1;
				z = Math.random() * 2 - 1;
				w = Math.random() * 2 - 1;

				vector.set( x, y, z, w ).normalize();

				orientations.push( vector.x, vector.y, vector.z, vector.w );

			}

			offsetAttribute = new THREE.InstancedBufferAttribute( new Float32Array( offsets ), 3 );
			orientationAttribute = new THREE.InstancedBufferAttribute( new Float32Array( orientations ), 4 ).setDynamic( true );

			geometry.addAttribute( 'offset', offsetAttribute );
			geometry.addAttribute( 'orientation', orientationAttribute );

			// material

			var material = new THREE.RawShaderMaterial( {

				uniforms: {
					map: { value: new THREE.TextureLoader().load( 'textures/crate.gif' ) }
				},
				vertexShader: document.getElementById( 'vertexShader' ).textContent,
				fragmentShader: document.getElementById( 'fragmentShader' ).textContent

			} );

			mesh = new THREE.Mesh( geometry, material );
			scene.add( mesh );

			renderer = new THREE.WebGLRenderer();
			renderer.setPixelRatio( window.devicePixelRatio );
			renderer.setSize( window.innerWidth, window.innerHeight );
			container.appendChild( renderer.domElement );

			if ( renderer.extensions.get( 'ANGLE_instanced_arrays' ) === null ) {

				document.getElementById( 'notSupported' ).style.display = '';
				return;

			}

			stats = new Stats();
			container.appendChild( stats.dom );

			window.addEventListener( 'resize', onWindowResize, false );

		}

		function onWindowResize( event ) {

			camera.aspect = window.innerWidth / window.innerHeight;
			camera.updateProjectionMatrix();

			renderer.setSize( window.innerWidth, window.innerHeight );

		}

		//

		function animate() {

			requestAnimationFrame( animate );

			render();
			stats.update();

		}

		function render() {

			var time = performance.now();

			mesh.rotation.y = time * 0.00005;

			var delta = ( time - lastTime ) / 5000;
			tmpQ.set( moveQ.x * delta, moveQ.y * delta, moveQ.z * delta, 1 ).normalize();

			for ( var i = 0, il = orientationAttribute.count; i < il; i ++ ) {

				currentQ.fromArray( orientationAttribute.array, ( i * 4 ) );
				currentQ.multiply( tmpQ );

				orientationAttribute.setXYZW( i, currentQ.x, currentQ.y, currentQ.z, currentQ.w );

			}

			orientationAttribute.needsUpdate = true;
			lastTime = time;

			renderer.render( scene, camera );

		}

	</script>

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